There are many factors to breeding and depending on what you are trying to breed, some are easier then others.
IMO, with Kribs, the first thing you need to do is find a compatible male and female pair. When I first started breeding kribs, I went through 4 differnt males for my female, because she didn't like any of them. Once I found a male she did like, it took awhile for the male to accept her.
Once that happened, I did lots of water changes and fed them a big variety of different foods. It took about 4 months before they spawned, but after the first spawning, they continued to spawn every 3-4 weeks. I had tons of kribs!
I hope that helps a little. Good luck!